Synthesis and Anti-Candida Activity of Cobalt(II) Complexes of Benzene-1,2-Dioxyacetic Acid (bdoaH2). X-Ray Crystal Structures of [Co(bdoa)(H2O)3]⋅3.5H2O and {[CO(phen)3](bdoa)}2⋅24H2O (phen = 1,10-Phenanthroline)

Abstract

Co(CH3CO2)2⋅4H2O reacts with benzene-1,2-dioxyacetic acid (bdoaH2) to give the Co2+ complexes [Co(bdoa)(H2O)3]⋅H2O (1a) and [Co(bdoa)(H2O)3]⋅3.5H2O (1b). Subsequent reaction of 1a with 1,10- phenanthroline produces [CO(phen)3]bdoa⋅10H2O (2a) and {[CO(phen)3](bdoa)}2⋅24H2O (2b). Molecular structures of 1b and 2b were determined crystallographically. In 1b the bdoa2- ligates the metal by two carboxylate oxygens and two ethereal oxygens, whereas in 2b the bdoa2- is uncoordinated. The Mn2+ and Cu2+  complexes [Mn(bdoa)(phen)2]⋅H2O (3) and [Cu(pdoa)(imid)2] (4) were also synthesised, 1a-4 and other metal complexes of bdoaH2 (metal = Mn²⁺, Co²⁺ ,Cu²⁺, Cu⁺ ) were screened for their ability to inhibit the growth ofhe yeast Candida albicans. Complexes incorporating the 1,10-phenanthroline ligand were the most active.